The meteoric rise in the popularity of home video players has created a tremendous need for high-throughput duplication of the magnetic tapes utilized by such players. Presently there are two general approaches to the volume duplication of video tapes, the first being real-time duplication wherein a plurality of copy tapes are recorded using program material read from a master, and contact printing wherein a copy tape is pressed against a master tape and a technique is used to transfer the program material from the master to the copy at the point where the two tapes overlap.
At present there are two practical contact methods in use for high speed magnetic tape duplication. The first, thermal duplication, disclosed in Billings et al, U.S. Pat. No. 4,882,636 demagnetizes the copy tape by elevating its temperature beyond its Curie point when in contact with the master so that it becomes remagnetized in accordance with the pattern recorded on the master as it cools. To ensure that the contents of the master tape are not degraded by the elevated temperature, the thermal process requires the use of a high Curie temperature, high coercivity metal-particle tape as the master tape, and CrO.sub.2 tape, as the copy tape.
The other practical form of high speed magnetic tape duplication, as disclosed in Nagaoka, et al, U.S. Pat. No. 5,095,390 utilizes the property of anhysteresis wherein a copy tape exhibiting a magnetic coercivity relatively less than that of the master tape is pressed against the master in the presence of a bias magnetic field causing the copy tape to demagnetize and realign in accordance with the master as the two pass by the head supplying the bias field.
Because these prior art duplication systems move the drum against a fixed transfer head, they only allow one copy tape to be duplicated from the master tape at any given time.
Additionally, the prior art systems only allow the master tape to operate in "shuttle mode" or "bin-loop" mode, but do not have the capability for both modes in a single duplicating apparatus. In shuttle mode, the master tape is unwound from a supply reel and collected onto a take-up reel during duplication, and rewound in between duplication cycles. In the bin-loop mode, the two ends of the master tape are spliced to form a continuous loop, with excess tape not actively involved in the transfer process being held in a containment bin.